Electronic devices, such as mobile phones, personal computers, personal digital assistants, and many others, utilize processors, memories, input/output (I/O) and other digital devices in order to provide their designed functionality to end users. These various digital devices are connected to one another using interconnects (also sometimes referred to as “busses” or “interfaces”), which convey data, signals and commands between or among the various devices, e.g., between processors.
Some interconnects, like many other electrical devices, are specified by standards. For example, in the Mobile Industry Processor Interface Alliance (MIPI), several standards are defined. One of these standards is called the MIPI Alliance Specification for High-Speed Synchronous Serial Interface (HSI) Physical Layer Version 1.01.00-September 2008. This standard documents the HSI interface, which is an interface designed to connect, for example, an application die to a cellular modem die in cellular handsets, but the HSI interface can also be used for other purposes. Various modem platforms in use today support the HSI standard as a modem interface for Inter Processor Communications (IPC). However, the HSI specification does not directly specify which speeds are supported on the interface, but instead discuss relative setup and hold time for the signals and that the receiver must support speeds between 1 and 100 Mbps. Moreover, there is no description of the protocol running on top of HSI and specifically no description of how the protocol shall be used to dynamically negotiate speeds on the link.
Accordingly, it would be desirable to provide methods, devices and systems for handling dynamic speed changes on HSI links.